Improvement in bit-stock fastening



nited tstr @wat (Milice.

CHAR-LES r. WHITMAN, OF OHARLEMON'I, MAssAOHUKsETTs, AssIGNOR 'ro'HIMsELF AND W. O. DODGE, OF WASHINGTON, DIs'rnIO'I OF COLUMBIA.

Letters .Patent No. 97,010, dated Norembe'r 16, 1869.

IMPROYEMENT IN' 'BIT-STOCK FASTENING.

The Schedule referred" to in these Letters Patent sind making bart ofthe saine.

To vall persons to whom these presents shall come Be itpknown that I,CHARLES P. WHITMAN, of Charlemont, of the county ot' Franklin, and Stateot' Massachusetts, have`in.'ented a new and useful Bit- Stock Fastening;and-do hereby declare the same to be fully described in the followingspecifcutiomgmd represented in the accompanying drawings, of' which-Figure 1 is a side view of a bit-stock provided with my invention.

Figures 2 and 3 are longitudinal sect-ions of the fastening, they beingtaken at right angles to each other.

Figure 4 is an end vicw ofthe fastening.

Figure 5 is a side view of the stock, as it appears without thecylindrical or tubular screw-nut.

Figure (i is a longitiulinal section of the screw-nut.

'lhe object 'ot' my invention is to produce a bit-stock into which bits,as ordinarily inade,can be inserted, without litting them especiallytherefor, as has geilerally to be done, and. which shall hold themtirmly,

and shall centre them by the simple act of fastening them in. v

'lo 'do this, I construct the lower end of the stock A, with a pyramidalrecess or socket, a, Ot' such a size as to permit the tapering end ofthe shank h of th bit to be inserted, as shown in figs. 2 and 3.

This recess or socket should be ot such a size that the smallest .endofthe largest shank may be inserted far enough to hold it and preventitfrom turning therein, and, at the same tinie,.receive the smallestshank, and prevent it from turning also. As bits are usually made withtheir shank-s varying but little in size, this can be readilyaccomplished.

U'pon the Outside ot' this end of the stock A, I outV or form ascrew-thread, b, as represented 'in fig. 5, this thread extending forsome distance along the stock.

I then provide a cup-shaped t'errule or cap, B, havigV a. correspondingscrew-thread formed on its inteiior surface, this cap being of -such asize as to fit,

easily on to the end of the stock, and screw thereon for a'n inch ortwo.

I'n lthe centre ot' the outer or closed end of this cap B,

I make a circular opening, d, large enough to receive the ,rounded stemof the bit below the shoulders ot' the shank h, this hole d being moreVclearly shown in iig. 4.

From this central hole d, I make a lateral opening, c, whielrextendsOutward to the outside of the cap,

' and extending a little way down on one side, where it of ythe bit tobe inserted through it into the socket a,.-

in the end ofthe stock A.

The hole d, I make conical, its greatest diameter heilig inside ot' thecap, so that when the bit is inserted and the cup B is screwed on to thestock A, this conical portion will bear upon vthe rounded shoulders ofthe shank 7i, andy thereby crowd the stem of the bit to the centre ofthe cap, thus centring of the bit truly in the stock.

The shoulder ot the'cap which surrounds the opening d, as the cap isscrewed up, engages over the shoulders of the shank li, thereby crowdingthe shank h into thc socket a, and thus holds the hit trinly'in thestock.

.lo remove the bit, it is only necessary to loosen the cap, by partiallyunscreu'ing it, when the bit can be taken ont, and another inserted.

By these means l am,able to produce a bit-stock thutwill receive,centre, and securely hohl any ordi- 1. A hit-stock, having a socket,ii., formed in its end, to receive theshunk ot' the bit, with a screwlthread formed on its exterior, and a cap, B, with a correspondinginternal screw-thread, with the openings d c formed in it, substantiallyas described.

2. The cap B, having a circular opening in its end, of such a size as toreceive` the stem Ot the bit, but not large enough to permit theshoulders ot' the shankl to pass through it, said opening being.connected, by lateral passage, with an opening in the s'ide ot' the cap,of sufficient size to permit the shank ofthe bit to be inserted therein,substantially as described.

CHARLES P. WHITMAN.

Witnesses R. H. EDDY, F. l. HALE, Jr.

